Editing Load Line Calibration values and ICCMax VRM shutdown values

BIOS/UEFI Modding BIOS Modding Guides and Problems
1

Hello, Gigabyte stuffed up the Z370 series when it came to the Coffee-Lake refresh series where they used 6 core CoffeeLake values for LLC and ICCMax amps. Is there anyway to edit the values set in the BIOS so I don’t get immediate reboots when doing XTU benchmark? To give some context this is what I am talking about

"VRM current protection levels are based on 8700k / 8086k (6 core processor) levels of 138 amps ICCMAX + a certain amount above. 9900k processors exceed 138 amps by a large margin (their ICCMAX is 193 amps, VRM current protection maxed out can raise this to 255 amps).

The same issue with loadline calibration. Default (Standard/Normal) for 6 core processors is 2.1 mOhms.
When a 9900k is installed, it should be 1.6 mOhms (8 cores) but it’s still 2.1 mOhms.

The LLC values were calculated here.
https://www.reddit.com/r/overclocking/co…_gigabyte_z370/

This is directly tied to the VRM overcurrent shutoff issue as well (the levels aren’t moved up for the 8 core processors).



@Mov_AX_0xDEAD @dsanke @CodeRush @Lost_N_BIOS @davidm71 Any ideas on how to edit the IFR setup to accommodate the right values?

2

What’s your motherboard model? I can try edit it via AMIBCP.
And I can not open the link above, it was corrupt.

3

@dsanke My model is Z370 Aorus Gaming 5. Here’s the corrected link: https://www.reddit.com/r/overclocking/co…_gigabyte_z370/

4

See if this one works , you can compare it with official BIOS to see what I’ve changed.
https://drive.google.com/open?id=1W4Qra0…3S7ebQiKJTWwOhc

5

I appreciate what you have done @dsanke Can you give me a step by step on how you did the mod?

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The board still reboots on XTU benchmark but I appreciate your effort on trying to help me.

7

I know @dsanke :slight_smile: He’s on my discord.

The loadline calibration settings are set by an i2c toolkit (hardware tools) that is made for IR 35201 programming. This tool is something end users can’t buy, and is used for setting values which are then programmed into the BIOS.
The “DC Loadline Override” (uOhm) value can be changed but I have no idea if this will affect the loadline calibration settings because these settings are set via i2c tools, not by DC Loadline Override (uOhm) in “Overclocking Performance Menu”.

I still have no idea if that value is even linked to anything. If setting this to “1600 uOhm” instead of “2100 uOhm” doesn’t change anything, there’s nothing a BIOS mod can really do. :frowning:

The VRM trip limits are also set by the IR 35201 programming i2c kit.

8

@dsanke btw please check your private message (or discord) if you have time. I had a question for you.

9

@Falkentyne Sent your findings to Gigabyte and now awaiting for them to replicate and send new BIOS to fix this issue. Hopefully they actually listen. The Z370 Aorus Gaming 5 uses an Intersil ISL95866 PWM Controller so I’m pretty sure IR35201 i2c kit wouldn’t be compatible?

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Oh I guess it’s the Gaming 7 that uses the 35201. That board has the same issue as yours also.

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Oh I guess it’s the Gaming 7 that uses the 35201. That board has the same issue as yours also.



Gaming 7 uses ISL 69138. Yeah they stuffed up the whole Z370 lineup. Awaiting Gigabyte to fix this problem. Will provide updates on their responses.

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@Falkentyne @dsanke Good news :slight_smile: Gigabyte has released me a beta BIOS, now I will test it out.
https://drive.google.com/open?id=1CBWA6p…wIZU15mZQ1F8LDf

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That was fast.
Does it improve anything?

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@Falkentyne I’m testing it out right now, will give you feedback on my results.

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Looks like it didn’t fix it, upon starting XTU benchmark, I get the reboot again. They probs didn’t bother increasing ICC max and also LLC still no fixed yet, high default voltage still present.

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@Falkentyne I got an update from Gigabyte, the issue is caused by High and Turbo Vcore LoadLine settings. Using standard LLC corrects this, AVX2 applications cause the PC to reboot when using the High/Turbo LoadLine settings. For LLC, they use Intel Gen4 VR Test Tool Base Kit to make sure it is 1.6 mOhms for Standard LLC. The VRM has a hardlimit of current it is allowed to suck which can’t be corrected.